APA (7th ed.) Citation

Hughes, D. A., & Norton, R. (2009). Vitamin D and respiratory health.

Chicago Style (17th ed.) Citation

Hughes, David A., and Rosemary Norton. Vitamin D and Respiratory Health. 2009.

MLA (9th ed.) Citation

Hughes, David A., and Rosemary Norton. Vitamin D and Respiratory Health. 2009.

Warning: These citations may not always be 100% accurate.